{"id":5598,"date":"2025-03-25T12:08:11","date_gmt":"2025-03-25T11:08:11","guid":{"rendered":"https:\/\/www.zsvltava.cz\/fyzika\/?p=5598"},"modified":"2025-06-26T12:25:49","modified_gmt":"2025-06-26T10:25:49","slug":"radioaktivita","status":"publish","type":"post","link":"https:\/\/www.zsvltava.cz\/fyzika\/?p=5598","title":{"rendered":"Radioaktivita"},"content":{"rendered":"<p><strong>Radioaktivita je schopnost n\u011bkter\u00fdch l\u00e1tek samovoln\u011b uvol\u0148ovat energii ve form\u011b z\u00e1\u0159en\u00ed. Tento jev objevili Henri Becquerel a man\u017eel\u00e9 Curieovi na konci 19. stolet\u00ed.<\/strong><\/p>\n<h2>Typy radioaktivn\u00edho z\u00e1\u0159en\u00ed:<\/h2>\n<p>&#8211; <strong>Alfa z\u00e1\u0159en\u00ed<\/strong> \u2013 \u010d\u00e1stice alfa jsou t\u011b\u017ek\u00e9 a maj\u00ed mal\u00fd dosah. Zastav\u00ed je ji\u017e pap\u00edr nebo lidsk\u00e1 k\u016f\u017ee.<br \/>\n&#8211; <strong>Beta z\u00e1\u0159en\u00ed<\/strong> \u2013 tvo\u0159\u00ed ho elektrony nebo pozitrony. M\u00e1 v\u011bt\u0161\u00ed pronikavost ne\u017e alfa z\u00e1\u0159en\u00ed, ale zastav\u00ed ho nap\u0159\u00edklad hlin\u00edkov\u00e1 f\u00f3lie.<br \/>\n&#8211; <strong>Gama z\u00e1\u0159en\u00ed<\/strong> \u2013 elektromagnetick\u00e9 z\u00e1\u0159en\u00ed s velkou energi\u00ed. Pro jeho zastaven\u00ed je pot\u0159eba olov\u011bn\u00e1 deska nebo siln\u00e1 betonov\u00e1 st\u011bna.<\/p>\n<h2>Vyu\u017eit\u00ed radioaktivity:<\/h2>\n<p>&#8211; V medic\u00edn\u011b (nap\u0159. radioterapie p\u0159i l\u00e9\u010db\u011b rakoviny)<br \/>\n&#8211; V energetice (jadern\u00e9 elektr\u00e1rny)<br \/>\n&#8211; V pr\u016fmyslu a v\u011bdeck\u00e9m v\u00fdzkumu (detekce materi\u00e1lov\u00fdch vad, datov\u00e1n\u00ed archeologick\u00fdch n\u00e1lez\u016f)<\/p>\n<h2>Nebezpe\u010d\u00ed radioaktivity<\/h2>\n<p>P\u0159i nadm\u011brn\u00e9m vystaven\u00ed m\u016f\u017ee radioaktivn\u00ed z\u00e1\u0159en\u00ed po\u0161kodit bu\u0148ky a zp\u016fsobit zdravotn\u00ed probl\u00e9my. Proto je d\u016fle\u017eit\u00e9 dodr\u017eovat bezpe\u010dnostn\u00ed opat\u0159en\u00ed.<\/p>\n<p>Radioaktivita je p\u0159irozenou sou\u010d\u00e1st\u00ed na\u0161eho sv\u011bta, ale je d\u016fle\u017eit\u00e9 s n\u00ed zach\u00e1zet opatrn\u011b a s respektem.<\/p>\n<h2>O radioaktivit\u011b na Nezkreslen\u00e9 v\u011bd\u011b<\/h2>\n<p><iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/TD-581sS11w?si=MBNh5V6vk_0CtfU0\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<h2>Historie objevov\u00e1n\u00ed radioaktivity<\/h2>\n<p><a href=\"https:\/\/www.zsvltava.cz\/fyzika\/?p=5625\">Conrad R\u00f6ntgen (1845\u20131923)<\/a> v roce 1895 p\u0159i experimentov\u00e1n\u00ed s katodov\u00fdmi paprsky objevil nov\u00fd druh pronikav\u00e9ho z\u00e1\u0159en\u00ed, kter\u00e9 nazval X-paprsky, dnes zn\u00e1m\u00e9 jako rentgenov\u00e9 z\u00e1\u0159en\u00ed. Toto z\u00e1\u0159en\u00ed m\u011blo schopnost proch\u00e1zet m\u011bkk\u00fdmi tk\u00e1n\u011bmi lidsk\u00e9ho t\u011bla a vytv\u00e1\u0159et obrazy kost\u00ed na fotografick\u00fdch desk\u00e1ch, co\u017e znamenalo revoluci v l\u00e9ka\u0159sk\u00e9 diagnostice.<\/p>\n<p><a id='Zp6q9qOdQTZ1NkobbhVKEA' class='gie-slideshow' href='http:\/\/www.gettyimages.com\/detail\/1344296735' target='_blank' style='color:#a7a7a7;text-decoration:none;font-weight:normal !important;border:none;display:inline-block;'>Embed from Getty Images<\/a><script>window.gie=window.gie||function(c){(gie.q=gie.q||[]).push(c)};gie(function(){gie.widgets.load({id:'Zp6q9qOdQTZ1NkobbhVKEA',sig:'c3T7sY7BzVMscZSu8gQVy_lEouLvx-ayo7sdrA9N3PQ=',w:'369px',h:'469px',items:'1344296735,1039845578,1282826879,1426570951',caption: true ,tld:'com',is360: false })});<\/script><script src='\/\/embed-cdn.gettyimages.com\/widgets.js' charset='utf-8' async><\/script><\/p>\n<p><strong>Henri Becquerel (1852\u20131908)<\/strong> byl francouzsk\u00fd fyzik, kter\u00fd v roce 1896 objevil p\u0159irozenou radioaktivitu. Motivov\u00e1n R\u00f6ntgenovou prac\u00ed, p\u0159i zkoum\u00e1n\u00ed fluorescen\u010dn\u00edch vlastnost\u00ed uranov\u00fdch sol\u00ed zjistil, \u017ee dok\u00e1\u017eou samovoln\u011b vyza\u0159ovat neviditeln\u00e9 z\u00e1\u0159en\u00ed, kter\u00e9 ovliv\u0148uje fotografick\u00e9 desky i bez p\u0159edchoz\u00edho vystaven\u00ed sv\u011btlu. Tento objev polo\u017eil z\u00e1klad pro dal\u0161\u00ed v\u00fdzkum radioaktivity.<\/p>\n<p><a id='BHuZ_SU1S851J6HUvLHnWg' class='gie-slideshow' href='http:\/\/www.gettyimages.com\/detail\/78963730' target='_blank' style='color:#a7a7a7;text-decoration:none;font-weight:normal !important;border:none;display:inline-block;'>Embed from Getty Images<\/a><script>window.gie=window.gie||function(c){(gie.q=gie.q||[]).push(c)};gie(function(){gie.widgets.load({id:'BHuZ_SU1S851J6HUvLHnWg',sig:'eCfiYYmlgxgN4PYv9MB_-zT3vGTt1bfY4fhs6MjNujs=',w:'375px',h:'594px',items:'78963730,514891060,463915131',caption: true ,tld:'com',is360: false })});<\/script><script src='\/\/embed-cdn.gettyimages.com\/widgets.js' charset='utf-8' async><\/script><\/p>\n<p><strong>Marie Curie (1867\u20131934)<\/strong> byla v\u00fdznamn\u00e1 fyzi\u010dka a chemi\u010dka polsk\u00e9ho p\u016fvodu, kter\u00e1 spole\u010dn\u011b se sv\u00fdm man\u017eelem Pierrem Curie roz\u0161\u00ed\u0159ila Becquerel\u016fv objev. V roce 1898 izolovali nov\u00e9 radioaktivn\u00ed prvky \u2013 polonium a radium. <a href=\"https:\/\/www.zsvltava.cz\/fyzika\/?p=2764\">Marie Curie<\/a> jako prvn\u00ed pou\u017eila term\u00edn &#8222;radioaktivita&#8220; a stala se prvn\u00ed \u017eenou, kter\u00e1 z\u00edskala Nobelovu cenu, a to dokonce dvakr\u00e1t \u2013 za fyziku (1903) a za chemii (1911).<\/p>\n<p><a id='nxwhutB1QFd2xtCEE8PVCQ' class='gie-single' href='http:\/\/www.gettyimages.com\/detail\/463965853' target='_blank' style='color:#a7a7a7;text-decoration:none;font-weight:normal !important;border:none;display:inline-block;'>Embed from Getty Images<\/a><script>window.gie=window.gie||function(c){(gie.q=gie.q||[]).push(c)};gie(function(){gie.widgets.load({id:'nxwhutB1QFd2xtCEE8PVCQ',sig:'Y7htpkcVaH2hUe90qy7O-ugraP2L3IPSsXvMveSy3Qk=',w:'393px',h:'594px',items:'463965853',caption: true ,tld:'com',is360: false })});<\/script><script src='\/\/embed-cdn.gettyimages.com\/widgets.js' charset='utf-8' async><\/script><\/p>\n<p><strong>Paul Ulrich Villard (1860\u20131934)<\/strong> byl francouzsk\u00fd fyzik a chemik, kter\u00fd v roce 1900 p\u0159i studiu radiace emitovan\u00e9 radiem objevil gama z\u00e1\u0159en\u00ed. Zjistil, \u017ee na rozd\u00edl od alfa a beta z\u00e1\u0159en\u00ed nen\u00ed ovlivn\u011bno magnetick\u00fdm polem. Pozd\u011bji, v roce 1903, <a href=\"https:\/\/www.zsvltava.cz\/fyzika\/?p=5401\">Ernest Rutherford (1871\u20131937)<\/a> pojmenoval toto z\u00e1\u0159en\u00ed jako &#8222;gama z\u00e1\u0159en\u00ed&#8220; a prok\u00e1zal, \u017ee jde o elektromagnetick\u00e9 z\u00e1\u0159en\u00ed s extr\u00e9mn\u011b kr\u00e1tkou vlnovou d\u00e9lkou.<\/p>\n<p>Objevy t\u011bchto v\u011bdc\u016f m\u011bly z\u00e1sadn\u00ed dopad na v\u011bdu a medic\u00ednu, zejm\u00e9na v oblasti l\u00e9\u010dby rakoviny a v\u00fdvoje jadern\u00e9 energie.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Radioaktivita je schopnost n\u011bkter\u00fdch l\u00e1tek samovoln\u011b uvol\u0148ovat energii ve form\u011b z\u00e1\u0159en\u00ed. Tento jev objevili Henri Becquerel a man\u017eel\u00e9 Curieovi na konci 19. stolet\u00ed. Typy radioaktivn\u00edho &#8230;. <\/p>\n","protected":false},"author":1,"featured_media":5607,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[76],"tags":[67,17],"class_list":["post-5598","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-atomy-a-zareni","tag-historie","tag-video"],"_links":{"self":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/5598","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5598"}],"version-history":[{"count":2,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/5598\/revisions"}],"predecessor-version":[{"id":6027,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/5598\/revisions\/6027"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/media\/5607"}],"wp:attachment":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5598"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5598"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5598"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}